DE1720241A1 - Process for the production of polyalkylene terephthalate - Google Patents

Description

DR. ILSE RUCH PATENT ADVOCATE

MUNICH 5

REICHE .3ACHSTR. 9 \

Polio A / 10967

R / P
6th

Allied Chemical Corporation. ^ New York., NY , USA

Process for the production of polyalkylene terephthalate

The invention relates to a method for producing linear, high molecular weight, colorless polyalkylene terephthalate and Copolymers thereof and those obtained by this process Terephthalates. These polymers have high melting points and are particularly suitable for extrusion transparent pollen, textile fiber ^ coatings and the like, the sioh especially for use in the Verpaokungsinduetrio suitable.

Polyalkylene terephthalates are usually produced by terephthalic acid in the presence of a catalyst (catalyst of the first process stage) with the corresponding

109833/187

Olykol converts to the Dlglykolterephthaläureester and this Then compound in the presence of a condensation catalyst condensed to the usual polymer.

A number of catalysts are known for the production of polyalkylene _{terephthalate (} including, for example, Antlmontrloxid. These catalysts were mainly chosen because of their good catalytic effect and the only slight discoloration of the polymer resulting from their use If the polyester becomes dark due to the catalyst, it is still a problem, especially if the polyesters are to be used for the production of textile fibers, etc. To prevent color formation, it is already known to use color inhibitors such as phosphoric acid, for example Although the first stage fails to deactivate the catalyst of the first stage, the 4er WUMiM is responsible for the formation of fouling, it has a negative effect on the polymer, that is, it catalyzes, for example, lifting reaction loaexi, the degeneration of Xtherverknapfuncen eto Xther links and the fiOh lMtdren themselves are AUOH dam Nooh unerwUaecht when they are present in small Meng "because ale herabaetsen the Soheelzpunltt you versehleohtern polyester and their resistance to degradation Mimm durdh Lloht, etc. Wäme.

109833/1971

BAD ORIQiNAL

The invention relates to a process for the production of a colorless, linear, high molecular weight polyalkylene terephthalate by pre-esters of terephthalic acid, a low-molecular dialkyl ester of terephthalic acid, an isomer of the acids or esters or a mixture of at least one of these compounds with a smaller amount of a modified terephthalic acid , a low molecular weight dialkyl ester, a modified terephthalic acid or a λ isomer thereof with an alkylene glycol with 2 to 8 carbon

atoms to the corresponding diglycol ester and polycondensation this intermediate compound at elevated temperature, which is characterized in that the polycondensation at a Temperature between 200 and 310T in the presence of a salt of trivalent antimony with a monocarboxylic acid with at least 12 carbon atoms, which at ZimnjGrtemperattJir one Liquid or mixable with the condensation syrup « performs.

The modified terephthalic acid, for example, to 1 eulfonierte to 20 £ terephthalic acid, a low molecular weight dialkyl ester of a modified terephthalic acid or a Iconeres thereof, let for example in an amount of 0.1 to 10 wt .- #, and preferably "1 to 5 wt -.% present.

109833/1878

According to the method of the invention; Polyalkylene terephthalates obtained have melting points of at least over 240 ⁹ C and me lot over 250%.

Glycols, which aloh for elno use in the process of Invention suitable are the low molecular weight glycols with 2 to 4 methylene groups, for example ethylene glycol, Propylene glycol, butylene glycol and mixtures thereof. Next «usable Glycols are trimethylene glycol, tetramethylene glycol, Pentamethylene glycol, hexane ethylene glycol, heptaroethylene glycol unfi ethane ethylene glycol.

For ¹ Ie esterification of terephthalic acid or to the umeatorn of the nieui'igaol "" kularen dialkylethers of torephthalstture, etc., the "lycoles are used in an amount between about 1 and 4 mol% per equivalent of terephthalic acid or dialkyl ester, etc." The esterification of terephthalic acid can be used in the presence of known catalysts "such as, for example, fialzsKure" p-toluenesulfonic acid etc. " Tin, WlSBUt, antimony, CaIoium and various other metals and metal salts, for example caloluma acetate, caolluracetate monohydrate and, in particular, zinc acetate.

103833/1871

The implementation of the first procedural stage, ie the reaction between the olylcol and the terephthalic acid, including the modified terephthalic acid and its isomers, takes place at a temperature of about 110 to 220t either at atmospheric pressure or at pressures up to about 10 itU and preferably at pressures in the range from about 8.1 to 10.5 "do. be performed. After the terephthalic acid and / or the modified acids have reacted with the glycol, the temperature of the reaction system is increased, and %

Excess aiykol is distilled off, usually under reduced pressure. Alternatively, as mentioned, the diglycol esters can also be obtained by unesters of low molecular weight allyl esters of terephthalic acid, including their isomers and the esters of modified acids, which can have, for example, up to 4 carbon atoms and, for example, methyl, ethyl, propylene, butyl, amyl - Or hexyl groups can be obtained old Olykol. Methyl terephthalate is preferably used as the low molecular weight diester. To effect the transesterification, the reaction mixture must be heated above the boiling point of the alcohol to be replaced, but must not be heated above the boiling point of the glycol. The transesterification can take place at temperatures down to XiCK and up to about 22QK and is preferably carried out at 150 to 2105! for about 1 to 5 hours or more until the alcohol is separated.

109833/1878

As mentioned, the transesterification can be carried out in the presence or absence of a catalyst, for example an alkali or alkaline earth metal or a salt thereof. If an alkali metal is used as the catalyst, this can be used in the form of an alcoholate, for example in the form of a Nacriur.w alcoholate, which is obtained by reacting the alkali metal with the alcohol, such as ethyl or methyl alcohol. The glycol terephthalic acid ester obtained is then heated to a temperature of up to about 310 ° C. in order to separate off excess glycol, preferably under reduced pressure.

As mentioned, it may be in order to be responsible for esterification or omesterification to shorten the required tent, it may be expedient to use a • catalytic converter. From the known catalysts βloh Jedooh many have proven to be unsuitable because they break down the polymer and thus lead to discoloration cause the same. Purpose of using a tneeter However, catalyst * in the first process stage is not

only an acceleration of the unsettling, but also the crumbling of a «high quality product. Catalysts which accelerate the (fasstsung, have usually had the Machte11 because * they ax cause a discoloration of the product, so DAFL been iemer a Kompromifl muffte be closed. Conduct That tan dl · esterification or transesterification in a sufficiently short tent had gewöhnlioh a catalyst can be used for this, some of those used for the first stage of the process

109833/187

BATH ORIGINAL

Catalysts were also found to be effective for the second stage of the process, i.e. polycondensation. All such Catalysts caused undesired degradation of iodooh ninan and gine discoloration of the polymer. Diccö Kataly.'irAoi-ra were also in combination: tiit various inhibitors and Antimony catalysts, for example antimony oxide, are used.

The catalyst of the araten stage to completion;

the Umsöb wetting oreten this stage by the inhibitor corresponds%

_t activated and then the Antitnonkatalysator "that has not been deactivated by the inhibitor, but the implementation of the second Verfahransstufe was catalyzed, the polymer ken without even a considerable degradation to bewix ^i, eye sets. All the antimony catalysts previously used for this purpose, however, were easily reduced during the reaction to a black substance which caused a gray discoloration of the polymer known as "antimony gray".

There are also catalysts for the first process stage which do not cause any significant degradation or discoloration of the polymer. However, these have not been found to be effective for the second stage of the process. These catalysts were often used with an antimony compound as a catalyst for the second process stage, where again the problem of ⁿ antimony ^{gray n} discoloration occurred.

109833/1878

This problem becomes with the use of the antonon catalysts solved according to the invention, since these antimony catalysts at those usually involved in spinning, extruding, etc. the mass applied temperatures do not cause any degradation of the polymer. In addition, when using the antimony catalyst According to the invention, a high production rate can be achieved, and transesterification and condensation can be carried out without Difficulty can be carried out under normal conditions in two stages of the process.

In the case of condensation, the Antlnonealz is preferably in one Amount in the range of about 0.005 to 0.7 ow.-ji des Terephthalate used. It has been found that the antimony salts, although the transesterification or esterification of the first stage of the process not or only slightly accelerate », but on the other hand no detrimental effect on these implementations either exercise and therefore, if desired, combine bit de »esterification · - or one metering catalyst is added to the starting mixture can be.

The condensation of the diglycol terephthalic acid ester formed as an intermediate compound then takes place at temperatures in the range from 200 to 310V and preferably about 225 to 310V or 240 to 280V, in the form of a cell under a different pressure, preferably under a pressure of 0.01 to 20 tea Hg · Di · The tent required for condensation is under these conditions

109833/1878

Usually in the range of 1 to 30 and preferably 2 to 10 hours, after this period a product with a reduced viscosity of at least 0.5 is formed. The duration of the condensation naturally depends on the QtQQq of the approach and the technology used, for example on whether the work is carried out in individual sessions or continuously. For example, when continuous condensation is used, the reactant mass is continuously stirred so that the vacuum used to rapidly separate the glycol is as effective as possible. The condensation is preferably carried out under subatmospheric pressure and preferably in an inert atmosphere, for example under nitrogen, or in the absence of oxygen or oxygen-containing oases.

Those for dl · esterification or transesterification and the condensation The necessary tents, of course, still depend on the Concentration of the catalyst, the temperature, the pressure and the desired viscosity of the final product.

For example, according to the invention, ethylene glycol can be reacted with dimethyl terephthalate in a molar ratio of 1: 1 to 4: 1 and preferably 1: 1 to 1) S1, the first process stage, ie the transesterification, at a temperature in the Bs ₁ r · Loh bio to 22 (K can be carried out in the presence of, for example, an alkali metal, alkaline earth metal or βInea salt thereof under atmosphere

109833/1871

QRIG / NAL

an amount of O ₄ Ol bla 0.5 MoI-Ji, based on the Qetrloht dea Xthyleneglykols, and preferably in an amount voriöf0Ϊ "- ^J '

at 0.07 mol-ίί, is used. . tosk; * ·

Xthylene glycol and terephthalic & uredlalkyleeter are so long not etched, until the Bls-hydroxyXthyl terephthalate is formed. Then the condensation of this diglycol ester takes place directly with removal of olymol and is continued for a long time until the Nolekulargewloht has reached the desired value.

The salts of trivalent antimony used according to the invention can be obtained by known methods. For example, a higher molecular weight monocarboxylic acid can contribute Temperatures from about 100 to 160t and preferably 130 to 145% neutralized with antleton oxide under RokfluSbedlngungen will. Excess metal or non-converted β antimony oxide are separated, for example filtered off, so that the ■■ Antimoasals surüok remains. Bine Welt «» Method · der The submission of the anti-ionic salts consists in the substitution of Antlfflonehlorld old the atrium salt of a higher molecular weight MonooarbonaSure, where Vatriwaohlorid and the corresponding Antleon salt are formed. "

The antimony compounds used geniKS of the invention have the formula Sb-B ₃ , wherein 8 is appropriate; "In an organized form the remainder of a simple or complex mixture of aliphatic monocarboxylic acids with at least 12 carbon atoms in the molecule"

is. Further salts which can be used according to the invention are the antimony salts of the higher molecular weight naphthenic acids at least 12 carbon atoms in HoIeIcUl.

The organic acids necessary for the preparation of the according to Antimony salts used in the invention are, for example, the monocarboxylic acids having at least 12 carbon atoms and preferably 12 to 22 carbon atoms each Molecule. These acids include the saturated fatty acids, such as lauric acid, trideoanic acid, myristic acid, pentadecane cure., Palmitic acid, margaric acid, stearic acid, nonadeoanic acid, Alcoholic acid, behenic acid, lignooeric acid, cerotic acid, Oo t ac obanic acid, malic acid, dopantanoic acid and mixtures of that.

Suitable unsaturated. Fatty acids are dodsoic acid, tvtradecenoic acid Trideoenoic acid, pentadeoenoic acid, hexadeoenoic acid, heptadeoenoic acid, Ootadeoensäture, My advised oleic acid, PalmitöleinsXure, "

Oleic acid, cetrolelic acid, linolenic acid and linolenic acid, etc.

Oeelgnete monoalkylalkanoic acids are 2-methyllauric acid, 7-propylcapric acid, 2-methyl myristic acid, 15-methyl palmitic acid, 2-butyl myristic acid, 2-methyletearic acid, 2-ethylstearic acid, 20-ethyl behenic acid, 2 «hexyl-tearic acid, 2-Deoy, stearic acid, etc. Suitable polyalkylalkanoic acids are 2-butyl-S-ethylnonylic acid, 5.7,11-turethyllauric acid,

2,2-dimethylstearic acid and 2> methyl-2-ethyl-aravic acid

109833/1878

⁸ ORIGINAL

The preferred acids are oleic acid, palmitic acid, lauric acid, Linoleic acid, linolenic acid and others at room temperature liquid or with the glycol-containing polymeri3ation mixture miscible acids.

Besides these acids is particularly preferred for the production of the antimony salts used according to the invention, tall oil acid,

P which is a complex mixture of fatty acids, abietic acid, _ Contains oleic acid and some saturated fatty acids, is. These «preferred catalysts, such as this Antimony salt of tall oil can still be labeled be that they are volatile up to at least 15 # during the polymerization, for example if they are one Vacuum of about 0.3 to 0.6 mm Hg at temperatures of about 275 to 28O * C. The Antlmonsale of tall oil acid can be made by, for example Anti-mono-ol "it the acid with stirring at ruokfIuQtewperatur

'^ Erklt, 1st neutralized to dit entire acid, such as on the

Acid number of the end product is recognizable.

As mentioned, the preferred antimonealites are the salts of higher molecular weight fatty acids and especially the salts of the complex fatty acid mixture called Tallttlskure. the tall oil acids required for the production of these antimony salts 1 * ribbon are available. They contain (1) resin acids (Abietic acid), (2) saturated fatty acids / eln & chlleeiloh ·

Stearic acid, palmitic acid and lauric acid, etc., (5) un-

109833/1878

saturated fatty acids, including oleic acid, linoleic acid and Linolenic acid, (4) small amounts of dmerized acids and some that cannot be sheltered, such as sterols. Unrefined taliols suitable for the purpose of the invention are composed, for example, as follows:

Tall oil

Resin acids Unsaturated:
oleic acid
Linoleic acid
Linolenic acid 20th
8th
22nd
4th
3
29 % Qosaturated:
Myrietic acid
Palmitic acid
Stearic acid
Alcoholic acid
Lauric acid - 25th
- 10
- 27 "
- 43 Abietic acid
Palustric acid
Neoabietic acid
Dihydroxyabietic acid
iEodextroplmarinic acid
not identified Inevitable
Phytoeterlne
higher molecular weight alcohols
Hydrocarbons 46
43
1 Fatty acids δ - 48
- 45
- 2 25th
5
35 - 8th - 35
- 15
- 60 '

109833/1878

The resin acid content of tall oil depends on the location of the forest

of the pines from which it is obtained. Beiapielsweiee

Tall oils au
Virginia trees contain only 30 % resin acids, while other tall oils can contain up to 55 to 60% resin acids. Refining the tall oil does not significantly change the proportions of resin and fatty acids; Every time odor-causing substances, such as mercaptans, and the disulphides and a considerable proportion of coloring substances are removed.

But since the tall oil acids of crude tall oil, the considerable Amounts, for example up to 60 #, of resin acids are obtained can coagulate in the refined acid mix Amounts of resin acids be present. Make the definition dee United States Department of Commerce are "tall oil fatty acids" from crude Tall oil derived products containing about £ 90 or more of free fatty acids, with any practical use with relatively high amounts of resin acids excluded «Ind. The tall oil acids available commercially contain considerable amounts of carbon more than 900 fatty acids and betruahtlioh less than io pounds Resin acids. You can also use commercially available tall oil acids for example have the following composition:

109833/1178

Resin acids few: ¹ ale IO

saturated fat 2 to 20

Oil fatty acids 45 to 70 Linolo acids O to 15 Linolens whores less than 2

dimerized acids 2 to 25

Unsaponifiable less than 5 Iodine number 60 to 110

In addition, there are no other tall oil acids on the market that contain 0.3 to 6 # resin acids and 0.3 bi · k% if iohtverselfbares. Since the poor color, the poor heat resistance and the unpleasant quality are due to the presence of non-soapable material, the highly refined particles which contain only small amounts of these materials are expediently used for the production of the antimony compounds used according to the invention. A refined tall oil of this kind has, for example, a Qardner color of 3 to 6, an acid number of 19 * 1 to 200, a verse if un number of about 196, an iodine number of about 130 and a resin acid content of about 0.6 to 1.5 * . The pyttsic acids present can be selected from, for example, 48% inoleic acid, 50% oleic acid and about 2% saturated acids, for example stearic acid, etc.

109833/1878

exist. The preferred tall oil acids are the highly refined or double fractionated tall oil acid mixtures of about 96.8 # of the fatty acids, for example 46 # linoleic acid, 48 # oleic acid and 2 # unsaturated acid, and about \% of the resin acids and 2.2% of unsaponifiables.

The polyesters produced by the process of the invention ^ have melting points above 24 (K and preferably above 250 <C.

These melting points are determined by differential thermal analysis, for example a sample of 5 to 8 mg first heated to 180 ° C. for 4 hours and then placed in the device (Stone Model 12B) in an aluminum dish. After the device has been set appropriately, the thermogram of the sample is recorded under nitrogen from room temperature to 30 ° C. That temperature "at which the curve is a stopping point" is used as the melting point. 01 ·! Tspreduzlerberkelt the Sohnelzpunkts- \ reading by this method cheats ♦ XX,

The characteristics of the end product naturally germinate neon be modified by inter alia to the Polymerisatlonsgenlseh. These losses can, for example, flame retardation amlttel, Removal agents, antistatic agents, adhesion improvers, Tub and LiohtstablUsatoren, pigments, Pltiorescent agents, brighteners, other polymers, crosslinking agents, Parstoffvorlaufer, bacterloststisohe means and the like. be.

109833/1878

BATH ORIGINAL

:, U Z 4 I.

Besides this material! «Could Po3?> Ester οβ ^τ ·,, 'ur.r nooh an organic« »Phospbit, beisrjjel.swel« = · «n? -. ', .-- "four aryl phosphite, as a means of de-activating. -rs

the first «, procedural stage added wen '·, .. d · ..'-. ■; · - ;; r.' _t ■■■ gates react wänreßd o? r- ^ a ^ f i.-a; ::. ., - .. Eeter and cause a Abfc.au vnc mr. ^ V € --f ^;,; - ^, - ^. Polymerisats, by adding a PbosD'norvnrr .. * · -. ;. nt =. hence polyester of better-white "· * - al ^ i>: a. ~ i /.- u -: ir ^ -: ... ::. Addition were received. irfie ϊκ? Γΐΐ · ς £ c : Tv £ r ..;: ". i: / ._ ί · l ,. . · • In · «such deactivator not imr-rsr i ^. / Ec» ..-, · ,,,, i-ra? · ;. with close catalyst ^ re? -n <Liaeoht »eir., v6 / f <, \ ;, ... Jh '. ': .. for example the Phos) p..Jt Kit den; K * tu * .vJia - _. .; ... er - · level, for example CaIc ijirsacetat ,. düi Caöir ■ ·: -: ^: the metal in the ester ^ E «Htiber merce- * τ: * ...! Λ. i'.iterial about, ßle .zu discarded Msr.css sn ce * ^ ioypftcr ·. ■■ · bi, iung depends of course on Ser UblicherveiSG · ourc ^ - da "^ * tr ·! Mae metal caused discoloration"preference;: ■ "Werder! Compounds ven trivalent« s> phosphorus, baiepi «·.:. 6c Acid, trlerylphoephite, etc.,

The products obtained after the process of the invention have a reduced viscosity of at least about 0.5 and% are suitable for the manufacture of solid threads by means of rubber tapes . The reduction in activity was carried out with a solution of a sample of Pc-y * merisate in purified "o". iorphenoi with 0.1 * in eiruir Kon £ «nfcration '/ on. '-, 5th S at 25W ^ Vntnr V *

109833 / ^ 973

a "standard Cannon-Fenske-W-bore ¹¹ Viskometera the efflux time of the solution (t) and dia AusfluSselt of the solvent (t) gemeseen, and the reduced viscosity was calculated according to the following Olelchung:

ⁿ rd - «

where ⁿ red "reduced viscosity

C = concentration of the polymer

In g / 100inl solution n _r - relative viscosity * t / t,

The color of the polymer or the degree of whiteness is used as the whiteness index like the one in American Dyestuff Reporter 54, No. 7 » Rarely determined methods described 246-251 (1965). This method is based on reflection measurements similar to the following Olelchung are evaluated:

W - 4b - 30

■ \ n W - WeIQgTAdIndex, based on magnesium oxide B β blue reflection value 0 »green reflection value

The polyesters obtained according dt process of the invention can have a ißgradindex ^f in the range of 85 to hüDen.

1 0 9 8 J 3/1 8 7 8

BATH ORIGINAL

The following examples justify the use of Antimony salts as condensation catalysts at Herat β llung of polyesters, for example of polyalkylene terephthalate en, according to the method of the invention.

example 1

1 separated from each other in ame Hoe ^ genie ie hanging device: Solid terephthalic acid and Kthylenglykol with a content of about 0.1 part by weight Si Antiir.ontallat (eimr Antimonselz valley 181 acid), which was distributed glelohiräQig therein were 1.8 MolverhMltnis introduced and processed there to form a smooth, homogeneous paste. The paste was transferred by means of "! ®"! Nor Zafanradpuw.p "" to an esterification vessel which was kept under a pressure of 0.42 atU and at a temperature of 24K. The water of reaction wurd * separated by liner RA it iÄlerkolonne. The Hasse mxru pumped to a Blitzeindampfer of the Veresterungsgefä3 * and brought out there with a ix Oegenstro "dasu Heisen inert Qas in contact wfthrend i

the Druok was lowered to about 1 atmosphere. The esterified product was then transferred into a container with its mechanism kept at a temperature of about 2 °. The reactor was equipped with glycol spray coadansem by which the theoretical amount of glycol was separated off at a pressure of 55 Hg.

This reactor was "You melt in another G" fH3

10983 3 / U78
AD ORIGINAL

-ac 1 ^ 203.4 Λ

(prt-finisher) Transferred, and the temperature was raised to about 28Ot increased while the pressure was decreased to about 2 mm Hg. The greater part of the nodh was in excess of the molar ratio separated to terephthalic acid from 1: 1 present oil. From this OefÄS the melt was put into an extruder (extruder-type finisher vessel) «which is under a print of 0.1 em Hg and In the the polymer at a temperature was held by 28Ot. The WelSgradIndex de « P flowing polymer was 93 and the reduced viscosity 0.65. The polymer had a melting point of 25 * t, determined by thennl's differential analysis. This Polymerlsat could grow higher to solid, even, endless threads QualItes are spun.

Example 2

About 0.10 part by weight of zinc acetate hydrate and 0.22 part by weight Antlmontrltallat (antimony salt of tall oil acid) Gltlohmxaig iced with 124 ow parts of ethylene glycol of 20t. The Oemlsoh was transferred to a reactor, after which it 194 parts by weight of molten dimethyl terephthalate with a Temperature of 150t were added. The transesterification took place in about 5 hours up to 150t to 220t with evaporation of methanol and Olykol. The methanol was continuously over a · Rectification column withdrawn, and the Olykol was in the Reactor brought back to Uok. After completion of the implementation »die was recognizable from the amount of condensed methanol, the recycling of the Olykol was interrupted. The reaction temperature

109833/1878

BATH ORIQINAL

was increased to 24θΐ, at which temperature 4o # of the excess Glycols were evaporated at atmospheric pressure. At this point, the product was transferred to a polymerization reactor with a stirrer, and there it was 0.85 parts by weight of a homogeneous solution of 74 # of an organic Phoaphits, for example triphenylpho3phit, and 26 # Antimonyallate (antimony salt of tall oil acid) added.

The organic phosphite is used to deactivate the conversion catalyst of the first process stage, for example a zinc compound, while the antimony tritallate forms the condensation catalyst. The Vakuumelnstellung carried out such that a Diiaok was adjusted from about 0.1 mm Hg in about 45 minutes while the temperature rose from 240 to 2 John ⁰ C. After about 4 hours in vacuo at 275 ^ the desired viscosity was reached. The stirring was interrupted, the vacuum was released by inert gas and the pressure for extrusion was increased to 4.2 atmospheres. The extruded polymer had a whiteness index of 91 and a reduced viscosity of 0.70, F 254T, determined by differential thermal analysis.

Example 3

For the purpose of comparison, the above examples repeated with the difference that with const practically the same conditions instead of the antimontallate an approximately

109833/1878

ORlQfNAL

equivalent amount of antimony trioxide was used: the polyester was obtained by Urnestora from 970 parts by weight of dimethyl terephthalate with 620 ow parts of ethylene glycol in present of 0.55 parts by weight of zinc acetate at an initial temperature from 170T up to a final temperature of 210T. The reaction took about 4 hours and 400 parts by weight of methanol were distilled off from the reaction mixture. These The intermediate compound was condensed with antimony oxide (SbgO,), the antimony catalyst was used in such an amount that 0.025 orammatomic antimony was present per mole of benzene ring. About 50 ow parts of Zwlechenverblndung were together with Stainless steel balls 0.18 mm in diameter into one 500 ml single-necked round bottom flask. The flask was in a Rincο circulation evaporator immersed in a molten salt of 20OT. The temperature rose to 29OT within 90 minutes elevated. By the time the temperature reached 28OT, the Pressure lowered and then further lowered to 0.1 mm Hg. The condensation was continued for about 4 hours at high temperature and low pressure. The polymer was Removed and tested in the molten state under nitrogen. The test results are shown in Table Σ.

109833/1678

catalyst

Antimony trilinoleate

Antlroon trioleate

Antinone trioxide

T a b e 11 e

Reduced ending OH F

Vlakoeltät COOH Oruppen * C

0.59

0.57

0.5Ί

31 1 ^ 8 252

WelBgradlndey 5 ^ώ 88 (white) 5 ^ 90 (white) 56 80 (gray)

The suitability of the initial catalysts used in the invention for the condensation of polyali lentil phthalate results from their best-practice against reduction discoloration of the polymer below a part to the reduction of antimony dta "to the metal during the Polym rla ^ ^ ^ tu zurückirafUhrtn is, 1st weeeotlioh that the Katnlyaatf> r Mi the meriaationetemperaturen possible reduktionafodt ISTT

TabeU

It

Ant ion compounds Required for the Beduktiöii
2UsIt ₄ minutes Sb-tr iac et at
Sb-trioxld T
9 Sb-tritallate 21st Sb trioleate <■ * Sb-trllinoleate
1 0 S 8?

From these values it follows that the antimony salts used according to the invention are significantly more resistant to a Reduction are than the antimony compounds previously used as catalysts in the production of polyalkylene terephthalates.

Example 4

About 580 parts by weight of terephthalic acid, 430 parts by weight of ethylene glycol and 0.068 mole each of that shown in Table III Catalysts, based on the weight of terephthalic acid, were placed in a 2-1 stainless steel flask. The lid, fastened with bolts, had openings for the Shaft of an agitator, a nitrogen inlet, a thermocouple and an outlet line connected to a pressure measuring device Mistake. The flask was heated by means of an electric helmet jacket.

After purging the high-purity nitrogen, the flask was closed and the paddle stirrer was set at 10 rpm circulated and the heater turned on. In an hour and fifteen minutes the druok rose to about 2.45 tu at a temperature of 220 "C. The stirrer was set to 18 rpm set. The valve in the drain line was on for 4 hours adjusted so that the pressure was kept at 2.45 atmospheres. During this time the temperature gradually rose to 24052, and after about 4 hours there was no further increase in pressure.

109833/1878 ORIGINAL BATHROOM

Then the pressure was released and the contents of the flask increased through a nozzle at the bottom of the steel piston into a 2 l cup drained. The interconnect formed was completely white.

Approximately 50 parts of this intermediate compound was placed in a 500 wl single shark flask. This was connected by a tapered connection (20/40) to a 500 ml stainless steel flask, and the steel flask was connected to a Rinco-Ural pump by means of a second tapered connection (20/40). The flask was placed in an oil bath and the ^three- quarters flask was placed in a bis-bath. The oil bath was heated to 280 ° C. in 11/2 hours while the flasks were rotated in a horizontal plane, the glass flask being about 40 pounds immersed in the oil. The pressure was determined to be 0.03 mm using a KcLaod. The polymerization was continued for about 2 hours under this pressure and at a temperature of about 2 °. Table XII summarizes the properties of the products obtained in this catfish.

109833/1871

T from β 11 β III

catalyst Reduced
viscosity P, ⁹ C colour Wiemutstannat 0.41 257 Gray BIeletannate 0.51 257 healing cream color Nickel stannate 0.55 255 Gray Nat riumbi smutat 0.58 25 ^ If Antimony oxide 0.62 250 η Nat rlumantlmonth 0.55 257 cream colored Ant ltnon sodium tart rat 0.51 257 light cream color Tetra-n-butyH-ortho-
titanate 0.50 242 beige Antimony salt of tall oil
situ re 0.70 254 know

From this table it can be seen that those with the known Catalysts obtained polymers a color between light- and dark gray, while the polymer obtained with the catalyst of the invention was white.

Example 5 About 0.10 part by weight of zinc acetate hydrate and 0.22 part by weight Antimony Trltallat (antimony salt of a TalltSlslure) were equal to '

"Aziger mixed with 124 parts by weight of ethylene glycol from 2OT.

The mixture was placed in a reactor, and 17 *, 6. Parts melted dimethyl terephthalate and 19.4 ow. Part "

109833/1878

~ 27 -

Dimethyl isophthalate were added at a temperature of 150 ⁰ C. The transesterification took place in about 5 hours at 150 to 2205; with a lid on methanol and glycol. The methanol was continuously withdrawn via a rectification column, while the Olykol was returned to the reactor. After the end of the reaction, which could be recognized by the amount of condensed methanol, the glycol recycling was interrupted. The reaction temperature was increased to 2 ¹ MK, and at this temperature 40 # of Olykolküberschusses were at Atnioaphärendruck, ie the amount Qlykol, which was ar.we in excess of the molar ratio to Terephthalafc of lit send removed. The product was then transferred to a polymerization vessel with a stirrer, and 0.85 parts by weight of a homogeneous solution of 74% tryphenyl phosphite and 26% tetraontallate (antimony salt of telloleic acid) were added.

organic phosphite is used for deactivation of the first Uuiesterungskatalysators Verfahrenastuie, serves during the ä Antimontritallat as a condensation catalyst. The pressure was first reduced to 0.2 mm Hg within about 45 meows, while the temperature rose from 240 to 20 ° C. After about 4 hours in a vacuum at 275 ⁵ C, the desired Viaco- »ITHt was achieved. Stirring was stopped, inert gas was introduced and the pressure was increased to 4.2 atmospheres by extrusion. The polymer had a melting point of 24θΌ. determined by thermal DAfferential analysis.

1 0 9 8 3 'i / ^ $ 87

Claims (1)

Claims Process for the production of a colorless, linear, high molecular weight Polyalkylene terephthalate by esterifying Terephthalic acid, a low molecular weight dialkyl ester of ^ Terephthalic acid, an isomer of acids or esters or a mixture of at least one of these compounds a minor amount of a modified terephthalic acid, a low molecular weight Dlalkylestr a modified Terephthalic acid or an isomer thereof with an alkylene glycol having 2 to 8 carbon atoms to give the corresponding diglycol ester and polycondensers of this interconnection at elevated temperature, marked by this I show a · t, datf.dan dl «polycondensation at a temperature • wipe 200 and 310 * in the presence of a salt of trivalent W. For antimony from a monocarboxylic acid, it is at least 12 Carbon atoms, which are a liquid at citrus temperatures or can be seen with the condensation media. 2. The method according to claim 1, characterized in that it is worthwhile the antonon salt of a hydrocarbon carboxylic acid as a condensation catalyst nit up to 22 carbon atoms is used. 109833/1878 j $. Method according to claim 1 or 2, characterized in that that as a condensation catalyst the salt of a fatty acid is used. 4. The method according to claim 3, characterized in that äaQ as a condensation catalyst the antimony salt of linoleum or oleic acid is used. 5. The method according to claim 1 or 2, characterized in that the antimony salt of tall oil acid as the condensation catalyst is used. 6. Method naoh one of the preceding claims «thereby characterized in that the condensation catalyst in a Amount of 0.005 to 0.7 ow .- #, based on terephthalate, is used. 7. Procedure after one of the "previous ones"! Claims, thereby (| characterized in that the condensation is carried out in the presence of a color inhibitor. 8. The method naoh claim 7 »characterized in that the Parbinhibitor an arylphosphite, especially triphenylphosphite, is used. 9. The method according to any one of the preceding claims, 109833M878 characterized in that the antimony salt is added during the esterification. »08813 / part